I never had a problem with 3com 3c509b or C.
They work vanilla with WIn3x , WinNT3,51 and Win95, Win WIn98. And above.
Windows should be able to pick it up automatically.
For DOS make sure you are using the correct driver.

dionb wrote:

Adding your own problem isn't going to help the OP 😉

Actually I posted precisely because it does. If one person posts a problem with symptoms A, B and C and theories X, Y, Z and then person 2 posts the same problem with symptoms B, C and D and theories W, X and Y, you can make a Venn diagram and deduce that symptoms B and C and theories X and Y are probably more valid, thereby narrowing the scope of the problem and helping to solve it.

😜

If OP has checked his IRQs and doesn't see a conflict then I'm going to vote the card dead as well. I have a 3C509 working no problem on my 486 in both DOS 6.22 and WFW. This was one of the most ubiquitous LAN cards of all time, if not THE most. I've installed and watched innumerable amounts of these cards just work right out of the box.

It also looks like that LAN transformer next to F1 has taken a beating, so who knows what this card has been through. The 3com chip may just be kaput.

You can get these on ebay for less than $16, I got my most recent one not too long ago for $5. There's a boxed 3c509B on ebay right now that probably wont get any bids (unless some interested party reads this post) ending in the next 24 hours.

Moogle! wrote on 2017-10-04, 23:26:

If that isn't the problem, try changing that BIOS optioning for hard disk RAM area from :300 to DOS 1K.

Thanks for this tip. This happened to me and is reproducible.

System configuration:

• Three 3Com 3c509B Etherlink III combo cards in one computer.
• Port/IRQ configuration of 0x300/10, 0x310/11, and 0x320/12.
• Non-PNP BIOS.

Windows 98 was refusing to use one of the cards so I used 3c5x9cfg.exe (version 3.2) to toggle its PNP option. This instantly bricked two of the adapters and gave the third an EEPROM checksum error.

The error condition was:

• 3c5x9cfg.exe returned "!!! ERROR !!! no NICs are installed in this computer".
• The Linux 3c5x9setup utility saw one of the card ports but couldn't parse it.
• The Linux pnpdump utility returned nothing.

The solution was:

1. Insert only one bricked card.
2. Set BIOS option Hard Disk Type 47 RAM Area = DOS 1KB.
3. Boot with something that is not the Windows 98 rescue disk. (eg: drdflash or FreeDOS)
4. Run PNPDSABL.BAT from 3Com EtherDisk 6.1 Disk 2.

Setting "DOS 1KB" is required to unbrick the 3c509, which is totally non-obvious.

dajhorn wrote on 2022-01-23, 05:45:

Windows 98 was refusing to use one of the cards so I used 3c5x9cfg.exe (version 3.2) to toggle its PNP option. This instantly bricked two of the adapters and gave the third an EEPROM checksum error.

Are you really sure that the 3Com configuration tool supports multiple cards in the same system?

Hi,
do you by any chance have a soundblaster 16 in your machine that was there before you put the etherlink in it?
I had a problem with the exact same symptoms and the trick was to just remove the soundblaster, reboot, let windows 95 do its pnp magic with the etherlink, and then put the soundblaster back in, let windows 95 do its pnp magic and poof it worked...
the other way round it didnt...
Was even repeatable with a NE2000 clone...
Ethernet first, soundcard always last

elianda wrote on 2022-01-23, 10:58:

dajhorn wrote on 2022-01-23, 05:45:

Windows 98 was refusing to use one of the cards so I used 3c5x9cfg.exe (version 3.2) to toggle its PNP option. This instantly bricked two of the adapters and gave the third an EEPROM checksum error.

Are you really sure that the 3Com configuration tool supports multiple cards in the same system?

Yes, screenshot attached.

audiocrush wrote on 2022-01-25, 15:17:

do you by any chance have a soundblaster 16 in your machine that was there before you put the etherlink in it?

Nope, no sound cards or other devices that use IRQs or DMAs.

After unbricking the cards one-by-one, Windows 98 SE is good with all three in PnP mode.

This 3com 3c509 was a very popular card back in 1990’s because it was supported in allot of operating systems.
If you have another computer with ISA slot then try it there.

Windows 3.11, Windows NT 351 and 4.0 , windows 95, windows 98 have drivers built in for this card so it should
Find the card and configure it automatically.

I wonder if running intels ICU would help clear up any pnp issues...